Remember this scene from the movie?

Oh yeah, even after so many years i still find it much better than all the other TV shows in this category (bar south park). Maybe it's nostalgia too, but i really keep enjoying it.
I just dislike the way the opening "couch gag" changed, i find it's getting more and more longer and boring, like if they are trying to do arts or something but i don't like.

The couch gags are added after the episode is completed, some episodes get everything done a few mins short of what is needed to fill up the full 30 min slot. Then they go a bit crazy and add a really long couch gag, in the older series it would just be a case of using the circus fanfare one which broke into all the characters doing a dance, was just a means to fill up where the episode had fallen short of time.